<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        .box{
            width: 420px;
            height: 420px;
            border: 1px solid green;
            margin:100px auto;
            padding:15px;

            transform:rotate(45deg) scale(0.7);
        }
        
        .box>div{
            width: 200px;
            height: 200px;
            float: left;
            background-color: green;
        }

        .box>div:nth-child(1),
        .box>div:nth-child(2){
            margin-bottom:20px;
        }

        .box>div:nth-child(1),
        .box>div:nth-child(3){
            margin-right:20px;
        }

    </style>
</head>
<body>
    <div class="box">
        <div></div>
        <div></div>
        <div></div>
        <div></div>
    </div>
</body>
</html>